Intracerebral Research Articles

Vitamin D Status and Spontaneous Intra Cerebral Hemorrhage: Would it be Able to Help?

AbstractBackground: Vitamin D deficiency has in like manner rose as a hazard factor for cerebrovascular stroke. It is ques-tionable if vitamin D status impacts the anticipation of patients who have created intracerebral hemorrhage. In Aswan gov-ernate, most of people had low vitamin D levels in spite of its sunny weather, as well as increased number of hemorrhagic stroke.Aim of Study: Consequently, our study planned to look at the connection between serum 25 (OH) D status and hem-orrhagic stroke, to clear up their relationship with stroke seriousness, and to evaluate its connection with functional outcome and mortality in our considered patients.Patients and Methods: This prospective cross sectional study directed on 125 patients with first time acute stroke with spontaneous intracerebral hemorrhage. All members exposed to full history taking, detailed clinical examination and neurological checking. Brain imaging was performed after hospital admission. Blood tests were drawn for appraisal of serum 25-hydroxyl vitamin D and parathyroid hormone on the first day of admission.Results: 44% and 40% of examined patients with intrac-erebral hemorrhage had lacking and inadequate vitamin D levels respectively. There was a relationship between intrac-erebral hemorrhage with vitamin D levels, and the severity of the stroke and functional outcome. In dead patients with intracerebral hemorrhage, a low vitamin D level was detectable.Conclusion: Vitamin D deficiency may have a relationship with acute intracerebral hemorrhage and its pervasive hazard factors among individuals in Upper Egypt (Aswan). Low levels of vitamin D are freely prescient for deadly strokes with more confirmation of negative result in acute intracerebral hemorrhage. Consequently, It may be a marker of more noteworthy comorbidity and a being causally identified with stroke proposing that vitamin D supplementation is a promising approach in the preventive action of strokes. Further studies are needed to investigate this relationship among different territories of Egypt and for stroke subtypes.

Abstract WP133: Intra Cerebral Atherosclerosis is the Major Risk Factor for Stroke in Post Coronary Artery Bypass Graft Surgery Patients

Introduction: Stroke is one of the most severe complications after Coronary artery bypass grafting (CABG) and is associated with high rates of morbidity and mortality. Hypothesis: We aimed to define the relationship between extracranial and intracranial carotid artery stenosis and the risk of stroke after CABG. Methods: A retrospective analysis of 1245 consecutive patients who underwent coronary artery bypass grafting (CABG) in our institution from March 2015 till March 2017 was performed. All of them had carotid duplex ultrasound as a routine preoperative assessment. Those patients who had severe extracranial carotid stenosis (>70%), underwent computed tomography angiogram of head and neck cerebral vessels. Our analysis was mainly focused on assessing the relation between incidence of post-CABG stroke and severity of intra and extra cranial cerebral atherosclerosis. Results: Of the 1245 patients who underwent coronary artery bypass grafting(CABG) the routine preoperative carotid Doppler revealed severe extracranial carotid artery stenosis of >70% in 160 patients, who eventually underwent computed tomography angiogram which has shown both extra and intracranial cerebral vascular stenosis in 124 patients. Total number of patients who had post CABG strokes are 42 (3.37%), out of which 39 (3.13%) had extensive extra and intracranial vascular stenosis whereas only 3 (0.24%) had isolated extracranial vascular stenosis. Patients with extensive extra and intracranial cerebral atherosclerosis has high rate of in-hospital strokes (within 14 days) compared with patients with isolated extracranial atherosclerotic disease. Conclusion: Extensive atherosclerosis including intra and extracranial cerebral arteries are major risk factors for stroke in patients undergoing CABG. Pre-operative assessment of both intra and extracranial cerebral arteries increases the probability of risk assessment in high risk CABG patients.

Experimental Infection of Goats with a Newly Isolated Strain of Akabane Virus that Causes Encephalomyelitis

In 2010, there was a large-scale outbreak of bovine encephalomyelitis in Korea, and 15 new strains of Akabane virus (AKAV) were isolated. To identify the pathogenicity of one of these strains, we infected adult goats with AKAV-7 via different routes. Twenty-five female goats were used in this study and were divided into five groups: intracerebral (IC) and intrasubarachnoid (IS) viral inoculation (n=8 each), intravenous (IV) inoculation (n=4), and vaccinated before IV inoculation (n=4), in addition to a negative control animal. All animals inoculated with AKAV-7 had AKAV-neutralizing antibodies at 6-8days post infection (dpi). During the experimental period, infected animals showed no clinical signs. In the IC group, 5/8 goats had non-suppurative encephalomyelitis affecting the cerebrum. Virus S RNA segments were detected in nearly all areas of the brain. In the IS group, 3/8 goats had encephalomyelitis affecting the cerebrum, cerebellum and spinal cord. At 7 and 21dpi, virus S RNA segments were found mostly in the spinal cord, especially around the area of injection (L5-L6). Antibody titres in the serum of the vaccinated group had an early onset and slightly increased titre compared with the IV group. Histopathologically, there were no obvious lesions in the central nervous tissues in the vaccinated group, while one of four goats in the IV group showed encephalomyelitis in the parietal lobe of the cerebrum. The newly isolated AKAV-7 can cause encephalomyelitis in goats after experimental injection. The attenuated AKAV vaccine currently used in Korea may provide partial protective immunity against AKAV-7 infection, but the real effect of the vaccine requires further investigation in goats.

Isolation and identification of the Newcastle disease virus from field outbreaks in broiler and layer flocks in Iraq

Newcastle disease is one of serious pathological problems and causes of vast economic losses during 2011-2016 in Iraq. The disease caused high mortalities in all types of poultry nevertheless of vaccination. In this study all samples were collected from infected flocks with clinical signs of the disease. Inoculation of chicken embryonated eggs was carried out for virus isolation, identification, Haemagglutination and Haemagglutination Inhibition assay. Using Reverse Transcriptase-Polymerase Chain Reaction to confirm the presence of the virus, Intra Cerebral Pathogenicity Index and Mean Death Time were used to confirm all the isolates that were velogenic. The important determinant of Newcastle disease virus pathogenicity is fusion protein that has been used for phylogenetic analysis. sequencing and compared genetically of Newcastle disease virus Iraqi isolate to publish sequences acquired from GenBank showed 99% sequence similarity to the Iran isolate IRI 1392k (KJ176996.1). It can concluded from these data that introduction new virus was occurred in Iraq.

Abstract 2455: Development of patient-derived orthotopic xenograft mouse models of pediatric low grade gliomas

Abstract Background: Low grade gliomas (LGGs) account for 1/3 of pediatric brain tumors. Despite favorable outcomes with current therapeutic strategies, some tumors still recur following total resection. New clinically-relevant pediatric LGG (PLGG) animal models that replicate this subset of aggressive tumors are therefore needed. Methods: Fresh tumor tissues from 36 PLGGs were collected. Self-renewal capacity was examined in vitro in 11 tumors with a neurosphere assay. Putative glioma stem cells (CD133+ and/or CD15+ cells) were analyzed in 23 PLGGs by flow cytometry (FCM). Formation of orthotopic xenograft tumors was examined by direct implantation of 25 PLGG tumor cells into the matched locations in the brains of SCID mice followed by serial tumor sub-transplantations. In addition to histo-pathological characterizations, BRAF V600E mutation was validated with pyrosequencing, and CDKN2A deletion with FISH. Results: The yield of viable tumor cells was low. Neurosphere formation was absent in 10/11 PLGGs after 37.6 ± 15.2 days. FCM analysis of 20 pilocytic astrocytomas and 2 gangliogliomas confirmed the presence of low levels (<1.5%) of CD133+ (CD133+/CD15− and CD133+/CD15+) cells, and relatively high fractions of CD133−/CD15+ cells (12.9 ± 20.1% in pilocytic astrocytomas and 67.9 ± 26.1% in gangliogliomas). Unlike 21 pilocytic astrocytomas, 1 grade II astrocytoma and 2 gangliogliomas that did not formed xenograft tumors after 219.9 ± 70.4 days of observations, a pleomorphic xanthoastrocytoma (PXA) (WHO grade II) formed intra-cerebral (IC) xenografts that have been serially subtransplanted 3 times in vivo. Similar to the patient tumor, xenografts from this model (IC-3635PXA) exhibited low cell proliferation (Ki67+ cells <10%), medium microvessel density, homozygous CDKN2A deletion and relatively low abundance of CD133+ (<2%). The GFAP+ and CD15+ cells in xenografts, however, were slightly reduced while the vimentin positive cells dramatically increased from 50% to 100% compared to patient tumor. The allele frequency of BRAF V600E mutation increased from 28% in patient tumor to 33%, 70% and 67% in passage I, II and III xenografts, respectively, and to 69% and 67% in cells grown in FBS-based media and serum-free media, respectively. All these biological changes were accompanied by extensive single cell invasion along blood vessels into normal mouse brains. Conclusion: This study demonstrated that the tumor take rate of PLGGs was low despite the presence of putative glioma stem cells. Nonetheless, we have successfully established a PXA xenograft mouse model and xenograft-derived 3635PXA cell lines which replicate key features of the original patient tumor and demonstrate both enrichment of the BRAF V600E mutant allele frequency and active invasive growth in mouse brains. This novel model system should facilitate biological studies and pre-clinical drug screenings targeting the BRAF V600E mutation in pediatric PXA. Citation Format: Mari Kogiso, Lin Qi, Frank K. Braun, Xiumei Zhao, Zhigang Liu, Holly B. Lindsay, Yuchen Du, Huiyuan Zhang, Sibo Zhao, Ching-Hua Liu, Vidya P. Mehta, Xiaoyun Shen, Jeffrey Murray, Laszlo Perlaky, Jack Su, Patricia Baxter, Adekunle Adesina, Donald W. Parsons, Xinyan Lu, Murali Chintagumpala, Xiao-Nan Li. Development of patient-derived orthotopic xenograft mouse models of pediatric low grade gliomas. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2455.

Associating Factors with Outcome (Modified Ranking Scale) of Spontaneous Intracerebral Haemorrhage Cases Attending At Tertiary Care Hospital, Udaipur (Rajasthan)

Study Question : spontaneous intracerebral hemorrhage (SICH) remains the deadliest and most disabling form of stroke. Objective: to find out clinical profile, identifying definite risk factors, , to assess the utility of (ICH) Score and Intra Cerebral Haemorrhage-Graded Scale (ICH-GS) as tools to predict outcome and to apply Siriraj score and the Guy Allen score to classify patients as infarcts and haemorrhages based on the clinical presentation as predicted by the scores. Methodolgy: Single center, prospective, descriptive study, Department of Internal Medicine/Neurology RNT Medical College, Udaipur from December 2012-13 conducted in 50 patients of Spontaneous Intracerebral Haemorrhage as confirmed by CT of the brain were selected .Patients on thrombolytics, anti-coagulants, Antiplatelets, Traumatic haemorrhage, Venous infarct with hemorrhagic Transformation, Aneurysmal bleeding, Bleeding disorders, Coagulation disorder, Malignancy, Toxic cause were excluded. Approval from ethical committee were obtained. The initial assessment on admission using Glasgow Coma Scale (GCS), the National Institute of Health Stroke Scale (NIHSS), (ICH) Score and the ICH Grading Scale (ICH-GS) were calculated. The Siriraj score and Guy Allen score ,(CT) Scanning of the Brain, the volume of the bleed was calculated using the ABC/2 technique. The bedside ABC/2 method, the CT slice with the largest area of haemorrhage was identified. Outcome was evaluated using the Modified Ranking Scale (MRS)The data thus obtained were analysed with the help Microsoft Excel 2007 and statistical software PRIMER. Result : Out of 50 patients, mean age of 63.46 years, Male :Female ratio was 1.27:1. No significant association of MRS was observed with gender and age hypertension SBP and DBP pulse pressure the site of bleed. All 50 patients had a supra-tentorial site of bleed. Cases with IVH , Glasgow Coma Scale on admission volume of the bleed of intracerebral haemorrhage ICH and ICH-GS were significantly associated with Outcome P<0.05S) The most common cause of death was respiratory depression, followed by aspiration pneumonitis which occurred in 41% of patients who developed complications.

Histopathological Studies on the Neuropathogenicity of the Iriki and OBE-1 Strains of Akabane Virus in BALB/cAJcl Mice

The OBE-1 strain of Akabane virus infects the fetus via the dam, resulting in abortion or congenital abnormalities in ruminants. In contrast, the Iriki strain of Akabane virus is highly virulent and causes encephalomyelitis by post-natal infection. To clarify the difference in pathogenicity between the two strains, BALB/cAJcl mice were inoculated either intraperitoneally or intracerebrally (IC) with either strain from 3 days to 8 weeks of age. Pathological examination revealed non-suppurative encephalitis in mice inoculated by either route with the Iriki strain. Virus antigens were distributed widely throughout the brain when the virus was inoculated into newborn mice, but distribution was limited to the brainstem in mice inoculated when 8 weeks old. However, brain lesions were observed only in mice inoculated with OBE-1 by the IC route when the mice were 3 days old, but these lesions were mild. To examine the manner of viral spreading, the Iriki strain was inoculated IC or intrastriatally into 8-week-old mice. Viral antigens were distributed prominently throughout the spinal cord as well as the brainstem and various cerebral nuclei,and were present with less prominence in the connective fibres. Virus antigens were also distributed in the subventricular zone, where neuronal stem cells exist. These results show that the neuroinvasiveness of the Iriki strain diminishes with age, while neurovirulence is maintained; however, for the OBE-1 strain both neuroinvasiveness and neurovirulence diminish with age. Furthermore, Akabane virus infects neuronal cells in the brainstem and spreads to the spinal cord via an unidentified transneuronal pathway.

Hydrogen Sulfide Ameliorates Homocysteine-Induced Alzheimer's Disease-Like Pathology, Blood-Brain Barrier Disruption, and Synaptic Disorder.

Elevated plasma total homocysteine (Hcy) level is associated with an increased risk of Alzheimer's disease (AD). During transsulfuration pathways, Hcy is metabolized into hydrogen sulfide (H2S), which is a synaptic modulator, as well as a neuro-protective agent. However, the role of hydrogen sulfide, as well as N-methyl-D-aspartate receptor (NMDAR) activation, in hyperhomocysteinemia (HHcy) induced blood-brain barrier (BBB) disruption and synaptic dysfunction, leading to AD pathology is not clear. Therefore, we hypothesized that the inhibition of neuronal NMDA-R by H2S and MK801 mitigate the Hcy-induced BBB disruption and synapse dysfunction, in part by decreasing neuronal matrix degradation. Hcy intracerebral (IC) treatment significantly impaired cerebral blood flow (CBF), and cerebral circulation and memory function. Hcy treatment also decreases the expression of cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) in the brain along with increased expression of NMDA-R (NR1) and synaptosomal Ca(2+) indicating excitotoxicity. Additionally, we found that Hcy treatment increased protein and mRNA expression of intracellular adhesion molecule 1 (ICAM-1), matrix metalloproteinase (MMP)-2, and MMP-9 and also increased MMP-2 and MMP-9 activity in the brain. The increased expression of ICAM-1, glial fibrillary acidic protein (GFAP), and the decreased expression of vascular endothelial (VE)-cadherin and claudin-5 indicates BBB disruption and vascular inflammation. Moreover, we also found decreased expression of microtubule-associated protein 2 (MAP-2), postsynaptic density protein 95 (PSD-95), synapse-associated protein 97 (SAP-97), synaptosomal-associated protein 25 (SNAP-25), synaptophysin, and brain-derived neurotrophic factor (BDNF) showing synapse dysfunction in the hippocampus. Furthermore, NaHS and MK801 treatment ameliorates BBB disruption, CBF, and synapse functions in the mice brain. These results demonstrate a neuro-protective effect of H2S over Hcy-induced cerebrovascular pathology through the NMDA receptor. Our present study clearly signifies the therapeutic ramifications of H2S for cerebrovascular diseases such as Alzheimer's disease. Graphical Abstract ᅟ.

Infratentorial intracranial pressure monitoring: a hazardous option or an indispensable post-operative tool?

Due to its restricted size and the critical structures it contains, the posterior cranial fossa (PCF) is challenging for the neurosurgeon and each procedure exposes the patient to early and dramatic post-operative supratentorial (acute hydrocephalus) and/or infratentorial (brain swelling and/or hemorrhage) complications. Patient's monitoring after infratentorial surgery remains challenging. Indeed, supratentorial Intra Cerebral Pressure (ICPs) monitoring may not reflect infratentorial ICP (ICPi). Moreover, early post-operative CT scan is often difficult to interpret and occurrence of complications is lately suspected in the presence of clinical signs of brainstem impairment (bradycardia, pupillary dilation).

Peripheral administration of tau aggregates triggers intracerebral tauopathy in transgenic mice

Peripheral administration of tau aggregates triggers intracerebral tauopathy in transgenic mice

Setting up a SPF Chicken Model for the Pathotyping of West Nile Virus (WNV) Strains

Birds play a central role in WNV epidemiology by spreading and amplifying the virus. Increasing numbers of WNV isolates are detected in Europe, and the virulence of these genetically variable isolates is not well characterized for birds. Therefore, we investigated whether SPF chickens could be a valuable avian model for the pathotyping of WNV strains. One-day-old SPF chickens were inoculated subcutaneously (SC) or intracerebrally (IC) with four lineage 1 WNV strains (Is98, It2008, Fr2000 or Kunjin) and were daily clinically monitored for 2 weeks after infection. Additionally, one-day-old SPF chickens were SC inoculated, and one-week-old SPF chickens were SC or IC inoculated with two Euro-Mediterranean isolates, Is98 and Fr2000, to sample blood and feathers at regular time points. These samples were analysed by WN NS2a-specific rRT-PCR and WN NS1 antigen-capture ELISA that were developed for the purpose of this study. Differences in strain virulence were evidenced after IC inoculation of one-day-old SPF chickens, with Is98 eliciting the highest mortality rates and Kunjin the lowest ones, while lethality of Fr2000 and It2008 was intermediate. Neither viral load in sera and feathers nor NS1 antigen in the serum correlated with the differential pathogenicity of Is98 and Fr2000. However, irrespective of the inoculated strain, younger chickens showed higher and longer-lasting viremias than older chickens. In all experimental groups, the detection window for viral RNA in feathers lasted up to 14 dpi. Altogether, the data presented in this study show that WNV strain virulence can be discriminated in a one-day-old SPF chicken model on the basis of mortality rates, while viremia and viral load in feathers appear to be age dependent rather than strain dependent.

Нейропсихологическая характеристика пациентов с ишемическим инсультом, обусловленным аномалиями церебральных артерий

Проведено нейропсихологическое обследование 67 пациентов с церебральным ишемическим инсультом (ЦИИ) с аномалиями интрацеребральных (ИЦА) и прецеребральных артерий (ПЦА), возраст больных от 21 года до 50 лет. Всем пациентам выполняли комплексное клинико-неврологическое, клинико-лабораторное и клинико-инструментальное исследование (включающее магнитно-резонансную томографию головного мозга в режиме ангиографии). У всех пациентов диагностировали аномалии ИЦА и ПЦА, а также их комбинацию. Нейропсихологические нарушения выявлены у всех пациентов с ЦИИ, обусловленным аномалиями ИЦА и ПЦА. В структуре нейропсихологических показателей поражения когнитивной сферы выявлены у 65 (97 %) пациентов в виде преддементных расстройств в 64,2 % случаев и в 28,4 % случаев — деменции легкой степени выраженности. Нарушения в эмоционально-личностной сфере выявлены у всех пациентов с ЦИИ, обусловленным ИЦА и ПЦА, в структуре которых наблюдался тревожный синдром у 31 (46,3 %) пациента, депрессивный — у 12 (17,9 %) и тревожно-депрессивный — у 24 (35,8 %).

Highly Efficient Prion Transmission by Blood Transfusion

It is now clearly established that the transfusion of blood from variant CJD (v-CJD) infected individuals can transmit the disease. Since the number of asymptomatic infected donors remains unresolved, inter-individual v-CJD transmission through blood and blood derived products is a major public health concern. Current risk assessments for transmission of v-CJD by blood and blood derived products by transfusion rely on infectious titers measured in rodent models of Transmissible Spongiform Encephalopathies (TSE) using intra-cerebral (IC) inoculation of blood components. To address the biological relevance of this approach, we compared the efficiency of TSE transmission by blood and blood components when administrated either through transfusion in sheep or by intra-cerebral inoculation (IC) in transgenic mice (tg338) over-expressing ovine PrP. Transfusion of 200 µL of blood from asymptomatic infected donor sheep transmitted prion disease with 100% efficiency thereby displaying greater virulence than the transfusion of 200 mL of normal blood spiked with brain homogenate material containing 103ID50 as measured by intracerebral inoculation of tg338 mice (ID50 IC in tg338). This was consistent with a whole blood titer greater than 103.6 ID50 IC in tg338 per mL. However, when the same blood samples were assayed by IC inoculation into tg338 the infectious titers were less than 32 ID per mL. Whereas the transfusion of crude plasma to sheep transmitted the disease with limited efficacy, White Blood Cells (WBC) displayed a similar ability to whole blood to infect recipients. Strikingly, fixation of WBC with paraformaldehyde did not affect the infectivity titer as measured in tg338 but dramatically impaired disease transmission by transfusion in sheep. These results demonstrate that TSE transmission by blood transfusion can be highly efficient and that this efficiency is more dependent on the viability of transfused cells than the level of infectivity measured by IC inoculation.

Role of apoptosis in rabies viral encephalitis: a comparative study in mice, canine, and human brain with a review of literature.

To evaluate the role of apoptosis in rabies encephalitis in humans and canines infected with wild-type street virus, in comparison with rodent model infected with street and laboratory passaged CVS strain, we studied postmortem brain tissue from nine humans, six canines infected with street rabies virus, and Swiss albino mice inoculated intramuscularly (IM) and intracerebrally (IC) with street and CVS strains. Encephalitis and high rabies antigen load were prominent in canine and human brains compared to rodents inoculated with street virus. Neuronal apoptosis was detectable only in sucking mice inoculated with CVS strain and minimal in street virus inoculated mice. In a time point study in suckling mice, DNA laddering was noted only terminally (7 days p.i.) following IC inoculation with CVS strain but not with street virus. In weanling and adult mice, apoptosis was restricted to inflammatory cells and absent in neurons similar to human and canine rabies-infected brains. Absence of neuronal apoptosis in wild-type rabies may facilitate intraneuronal survival and replication while apoptosis in inflammatory cells prevents elimination of the virus by abrogation of host inflammatory response.

Experimental intracerebral vaccination protects mouse from a neurotropic virus by attracting antibody secreting cells to the CNS

In previous studies, we showed that intracerebrally (IC) immunized mice had antigen-specific antibodies (Abs) in cerebrospinal fluid and could survive lethal doses of transneurally spreading viruses. To better understand the mechanisms behind this, immune responses in both the central nervous system (CNS) and lymphoid organs following intracerebral immunization against pseudorabies virus (PRV) were investigated by focusing on antibody secreting cells (ASCs). IC immunized mice had significantly higher PRV-specific serum Abs and neutralizing Abs titers than SC immunized mice. Spleen and cervical lymph nodes (CLNs) of IC immunized mice produced significantly more PRV-specific Abs than that of SC immunized mice. ASCs, immunoglobulin and mRNAs of IgG, CXCL9, 10, 13 and BAFF were predominantly detected in the brain of IC immunized mice, but not in SC immunized mice. IC immunized mice (86%) survived more than subcutaneously (SC) immunized mice (33%) by suppression of virus propagation, when PRV was inoculated directly into the brain. In conclusion, IC immunization induced more effective immune responses to protect the CNS from PRV infection by attracting ASCs into the CNS and inducing much more PRV-specific serum neutralizing Abs. This approach may have important implications as a novel treatment procedure for neurotropic virus infections in both humans and animals.

Experimental interspecies transmission studies of the transmissible spongiform encephalopathies to cattle

Prion diseases or transmissible spongiform encephalopathies (TSEs) of animals include scrapie of sheep and goats; transmissible mink encephalopathy (TME); chronic wasting disease (CWD) of deer, elk and moose; and bovine spongiform encephalopathy (BSE) of cattle. The emergence of BSE and its spread to human beings in the form of variant Creutzfeldt-Jakob disease (vCJD) resulted in interest in susceptibility of cattle to CWD, TME and scrapie. Experimental cross-species transmission of TSE agents provides valuable information for potential host ranges of known TSEs. Some interspecies transmission studies have been conducted by inoculating disease-causing prions intracerebrally (IC) rather than orally; the latter is generally effective in intraspecies transmission studies and is considered a natural route by which animals acquire TSEs. The "species barrier" concept for TSEs resulted from unsuccessful interspecies oral transmission attempts. Oral inoculation of prions mimics the natural disease pathogenesis route whereas IC inoculation is rather artificial; however, it is very efficient since it requires smaller dosage of inoculum, and typically results in higher attack rates and reduces incubation time compared to oral transmission. A species resistant to a TSE by IC inoculation would have negligible potential for successful oral transmission. To date, results indicate that cattle are susceptible to IC inoculation of scrapie, TME, and CWD but it is only when inoculated with TME do they develop spongiform lesions or clinical disease similar to BSE. Importantly, cattle are resistant to oral transmission of scrapie or CWD; susceptibility of cattle to oral transmission of TME is not yet determined.

Improvement of brain energy metabolism and cholinergic functions contributes to the beneficial effects of silibinin against streptozotocin induced memory impairment

Recently, silibinin, a clinically used hepatoprotectant, has been reported to prevent amyloid beta induced memory impairment by reducing oxidative stress and inflammation in mice brain. However, the exact mechanism of neuroprotective effect of silibinin has not been properly studied especially in context of brain energy metabolism and cholinergic functions, the essential factors that undergo impairment in Alzheimer's disease. Therefore, the present study investigated the effect of silibinin on impairment in memory, brain energy metabolism and cholinergic function following intracerebral (IC) streptozotocin (STZ) administration in mice. STZ (0.5 mg/kg), administered twice at an interval of 48 h, caused significant memory impairment tested by Morris water maze. Further, STZ significantly decreased ATP and increased synaptosomal calcium level in mice brain. Increased oxidative and nitrosative stress was also observed in IC STZ injected mice brain. STZ IC induced memory impairment is associated with increased activity and mRNA expression of acetylcholinesterase (AChE) and decreased α-7 nicotinic acetylcholine receptor (α-7-nAChR) mRNA expression in mice brain. Pretreatment with silibinin (100 and 200 mg/kg, po) attenuated STZ induced memory impairment by reducing oxidative and nitrosative stress and synaptosomal calcium ion level. Further, silibinin dose dependently restored ATP level indicating improvement in brain energy metabolism. The activity and mRNA expression of AChE was restored by silibinin. Moreover, α-7-nAChR mRNA expression was significantly increased by silibinin in STZ treated mice brain. The present study clearly demonstrates that beneficial effects of silibinin in STZ induced memory impairment in mice is due to improvement in brain energy metabolism and cholinergic function.

Pathogenicity of different rabies virus isolates and protection test in vaccinated mice

This study was aimed to evaluate and compare the pathogenicity of rabies virus isolated from bats and dogs, and to verify the efficacy of a commercial rabies vaccine against these isolates. For evaluation of pathogenicity, mice were inoculated by the intramuscular route (IM) with 500MICLD₅₀/0.03 mL of the viruses. The cross-protection test was performed by vaccinating groups of mice by the subcutaneous route and challenged through the intracerebral (IC) route. Isolates were fully pathogenic when inoculated by the IC route. When inoculated intramuscularly, the pathogenicity observed showed different death rates: 60.0% for the Desmodus rotundus isolate; 50.0% for dog and Nyctinomops laticaudatus isolates; 40.0% for Artibeus lituratus isolate; 9.5% Molossus molossus isolate; and 5.2% for the Eptesicus furinalis isolate. Mice receiving two doses of the vaccine and challenged by the IC route with the isolates were fully protected. Mice receiving only one dose of vaccine were partially protected against the dog isolate. The isolates from bats were pathogenic by the IC route in mice. However, when inoculated through the intramuscular route, the same isolates were found with different degrees of pathogenicity. The results of this work suggest that a commercial vaccine protects mice from infection with bat rabies virus isolates, in addition to a canine rabies virus isolate.

Intracerebral vaccination suppresses the spread of rabies virus in the mouse brain

To investigate the efficacy of intracerebral (IC) immunization in preventing viral spread in the brain, we immunized mice with inactivated rabies virus via the subcutaneous (SC) or IC route, followed by administration of a lethal dose of rabies virus (challenge virus standard strain), directly into the brains of immunized mice. Progressive paralytic neurological signs were observed in control and 75% of SC immunized mice, whereas only 20% of IC immunized mice exhibited symptoms. Neutralizing antibody titers in blood plasma were significantly elevated in SC and IC immunized mice, with the highest levels seen in IC immunized mice. Analysis of whole brain lysates revealed a strong induction of immunoglobulin in the brains of IC immunized mice that had virus neutralizing activity. Histopathological examination of brain tissue revealed mild encephalitis and disseminated viral antigen in control and SC immunized mice, but rare in IC immunized mice. These results suggest that IC immunization induces a preventive humoral immune response against intracerebrally inoculated rabies virus. Induction of neutralizing antibody in cerebrospinal fluid represents a putative therapeutic measure for the treatment of rabid animals and humans.

Protective effect of curcumin against intracerebral streptozotocin induced impairment in memory and cerebral blood flow

Aims The aim of the present study is to investigate the effect of curcumin on cerebral blood flow (CBF), memory impairment, oxidative stress and cholinergic dysfunction in intracerebral (IC) streptozotocin (STZ) induced memory impairment in mice. Main methods Memory impairment was induced by STZ (0.5 mg/kg, IC) administered twice with an interval of 48 h in mice. Memory function was assessed by Morris water maze and passive avoidance test. CBF was measured by Laser Doppler Flowmetry (LDF). To study the preventive effect, curcumin (10, 20 and 50 mg/kg, PO) was administered for 21 days starting from the first dose of STZ. In another set of experiment, curcumin was administered for 7 days from 19th day after confirming STZ induced dementia to observe its therapeutic effect. Biochemical parameters of oxidative stress and cholinergic function were estimated in brain on day 21. Key findings The major finding of this study is that STZ (IC) caused a significant reduction in CBF along with memory impairment, cholinergic dysfunction and enhanced oxidative stress. Curcumin dose dependently improved CBF in STZ treated mice together with amelioration of memory impairment both in preventive and therapeutic manner. Significance The present study clearly demonstrates the beneficial effects of curcumin, the dietary staple of India, on CBF, memory and oxidative stress which can be exploited for dementia associated with age related vascular and neurodegenerative disorders.